Device for operating on tyres of &#34;SYSTEM PAX&#34; type and the like

ABSTRACT

A device for operating on tires comprising an outer carcass and an inner toroidal ring of deformable material; said device comprises a base which supports means for supporting the outer carcass of the tire, and movable means for extracting or inserting said ring from or into said carcass, said latter movable means being provided with at least one appendix arranged to interact with a portion of the edge of said ring.

[0001] This invention relates to a device for operating on those typesof tire which enable the vehicle to travel even in the case of apuncture or of insufficient inflation pressure.

[0002] Tires of the stated type, such as so-called System Pax tiresproduced by the MICHELIN Company enable the vehicle to travel even whentheir inflation pressure is very low or close to zero.

[0003] These tires, which are described in French patent application FR92/15061 and FR 93/14702, comprise not only the outer carcass but also aseparate toroidal support ring of elastomer rubber, which is housed inan appropriate seat provided in the well of the wheel rim.

[0004] When the tire is removed from the wheel rim, said toroidal ringremains inside said outer carcass, hence to replace or repair thecarcass said toroidal support ring has to be extracted and thenreinserted.

[0005] To extract the ring from and then replace it into the outercarcass requires considerable force on the part of the operator, thisforce being mainly due to the rigidity of said elastomer ring and therigidity of the carcass, and is also partly due to the uncomfortableposition in which the operator is compelled to work.

[0006] The object of the present invention is to solve the stateddrawbacks within the framework of a rational and reliable solution.

[0007] The invention attains said object by providing a device whichenables the toroidal ring to be extracted from the carcass, and thenreinserted therein, automatically without the operator needing to applyany physical force.

[0008] The device of the invention can be associated with a tire removalmachine or be a separate accessory.

[0009] Said device comprises a lower base provided on one side withmeans for supporting in the correct working position the tire outercarcass from or into which said toroidal ring is to be extracted orinserted, and provided on the opposite side with means for extracting orinserting said toroidal ring. Said means for supporting the tire outercarcass are adjustable in height to enable the tire to be positioned inthe correct working position.

[0010] Said means for extracting or inserting said toroidal ringcomprise a pneumatic or hydraulic cylinder-piston unit, with the rod ofwhich there is associated at least one tool provided with at least oneappendix for gripping the edge of said ring.

[0011] In a preferred embodiment said rod presents two appendices forgripping the edge of said ring, one provided to grip the edge of saidring only during its extraction from the tire outer carcass, and theother provided to grip said ring only during its insertion into the tireouter carcass.

[0012] The special characteristics of the invention are stated in theclaims.

[0013] The operational and constructional characteristics of theinvention will be apparent from the ensuing description of a preferredembodiment thereof given by way of non-limiting example and illustratedon the accompanying drawings.

[0014]FIG. 1 is a partly cut-away side view of the device of theinvention.

[0015]FIG. 2 is a partly cut-away side view of the device of theinvention during the extraction of the toroidal ring from the outercarcass of the tire.

[0016]FIG. 3 is a view of FIG. 2 taken from III.

[0017]FIG. 4 is a partly cut-away side view of the device of theinvention during the of the extraction of the toroidal ring from theouter carcass of the tire.

[0018]FIG. 5 is a partly cut-away side view of the device of theinvention during the insertion of the toroidal ring into the tirecarcass.

[0019]FIG. 6 is a partly cut-away side view of the device of theinvention on termination of insertion of the toroidal ring into the tirecarcass.

[0020] Said figures show the device 1, which comprises a base 2 ofparallelepiped shape, provided to its right with the means 3 forsupporting the tire P of SYSTEM PAX type produced by the MICHELINCompany, comprising the carcass 4 and the separate toroidal ring 5 ofelastomer rubber, located inside it.

[0021] On the opposite side of said base 2 there is fixed a U-shapedsupport 6 which supports means 7 for extracting or inserting said ring5.

[0022] From the upper side of said base 2 there upwardly projects anabutment element which in the illustrated example consists of anL-shaped tubular element 8, against which the sidewall 40 of the tirerests during the extraction and insertion of said ring 5.

[0023] In greater detail, with reference to FIGS. 1 and 3, said supportmeans 3 for the tire P comprise two equal bars 30 and 31, one end ofwhich is hinged to the base 2 and presents a toothed portion 300. Thetoothed portions 300 of the two bars 30 and 31 mutually engage so thatrotating one of the bars causes the other to rotate. The two bars 30 and31 support at their free end two cylindrical pins 32 on which the treadof the tire P rests. To the bar 30 there is also fixed a plate 33, tothe free end of which there is fixed a catch 34, the locking element 35of which can be inserted into a series of holes 36 in the base 2, whichare aligned along a circumferential arc.

[0024] The means 7 for the extraction or insertion of said ring 5comprise a pneumatic cylinder-piston unit 70, the casing 700 of which ishinged to the rod 6 by usual means, and which is free to rotate aboutits hinge point.

[0025] It should be noted that the axis of said cylinder-piston unit 70lies in the plane passing through the center of said carcass 4.

[0026] The rod 701 of the cylinder-piston unit 70 carries at its freeend a profiled tool 71 comprising two appendices 710 and 711 whichpresent a concave portion 712 for gripping said ring 5.

[0027] To the free end of the casing 700 there is fixed a fork-shapedmember 73 against which the top of said ring 5 rests during itsextraction from the carcass 4 of the tire P. Essentially, said member 73prevents the ring 5 from jamming between said rod 701 and said casing700.

[0028] The device 1 of the invention is operated via a switch 9, bywhich the operator controls its operation.

[0029] Before describing the operation of the invention it should benoted that the edges 41 and 42 of the carcass 4 of the tire P havedifferent diameters at their beads.

[0030] FIGS. 1 to 4 show the various operating stages involved inextracting the ring 5 from the carcass 4 of the tire P.

[0031] With reference to the figures, the operator has firstly to placethe carcass 4, carrying in its interior the ring 5, on the pins 32,taking care to orientate the carcass 4 such that its larger diameteredge 41 faces the tubular element 8.

[0032] The operator then adjusts the height of the pins 32, i.e. theorientation of the bars 30 and 31, on the basis of the diameter of thetire P, so that the sidewall 40 of the carcass 4 of the tire P restsagainst the upper horizontal part of said tubular element 8. Havingdetermined the correct height, the bars are locked in position by thecatch 34.

[0033] At this point, while supporting the casing 700, the switch 9 isoperated to cause complete extraction of the rod 701 from the casing 700of the cylinder-piston unit 70, so that the tool 71 passes through thecentral hole in the ring 5. The appendix 710 of the tool 71 is thenpositioned as shown in FIG. 1 and the rod 701 made to retract. By thismeans, the upper portion of the ring is extracted from the carcass 4 bydeforming as shown in FIG. 2. By continuing to retract the rod 701, thering 5 is brought into the configuration shown in FIG. 4, i.e. into aposition substantially perpendicular to the carcass 4. From saidposition the operator can manually extract the ring 5 from the carcasswithout exerting any force.

[0034]FIGS. 5 and 6 shown the operating stages involved in inserting thering 5 into the carcass 4 of the tire P.

[0035] For this purpose the operator has firstly to position the carcass4 on the pins 32, taking care to orientate it such that its smallerdiameter edge 42 faces the tubular element 8.

[0036] Having rested the carcass 4 on the pins 32, the operatorpositions it at the correct working height by orientating the bars 30and 31, and locks them in the correct position by means of the catch 34,so that the sidewall 40 of the carcass 4 of the tire P rests against theupper horizontal part of said tubular element 8.

[0037] The operator then inserts the lower end of the ring 5 into thecentral hole in the carcass 4, as shown in FIG. 5 with dashed lines, andthen extracts the rod 701 of the cylinder-piston unit 70, so that thetool 71 passes through the hole in the ring 5. At his point the operatorrotates the tool 71 through 180°, and hooks the appendix 711 of the toolto the upper edge of said ring 5, as shown in FIG. 5. By means of theswitch 9 he then retracts the rod 701, which as it retracts inserts thering 5 into to the carcass 4, as shown in FIG. 6.

1. A device for operating on tires (P) comprising an outer carcass (4)and an inner toroidal ring (5) of deformable material, characterised bycomprising a base (2) which supports means (3) for supporting the outercarcass (4) of the tire (P), and movable means (7) for extracting orinserting said ring from or into said carcass (4), said latter means (7)being provided with at least one appendix (72) arranged to interact witha portion of the edge of said ring (5).
 2. A device as claimed in claim1 , characterised in that said means (3) for supporting the carcass (4)of the tire (P) are adjustable in height on the basis of the diameter ofthe carcass (4) of the tire (P).
 3. A device as claimed in claim 2 ,characterised in that said means (3) for supporting the carcass (4) ofthe tire (P) comprise two height adjustable pins (32) on which the treadof the tire (P) rests, and at least one abutment element against which aportion of the sidewall (40) of the carcass (4) rests.
 4. A device asclaimed in claim 3 , characterised in that said abutment element is anL-shaped tubular element (8) supported by said base (2).
 5. A device asclaimed in claim 1 , characterised in that said movable means (7) forextracting or inserting said ring from or into said carcass (4) comprisea cylinder-piston unit (70), the casing (700) of which is hinged to asupport (6) branching from said base (2), and the rod (701) of which isprovided with said at least one appendix (710, 711) for gripping aportion of the edge of said ring (5).
 6. A device as claimed in claim 5, characterised in that the axis of said cylinder-piston unit (70) liesin the plane of symmetry of said pins (32).
 7. A device as claimed inclaim 5 , characterised in that said at least one appendix (710, 711) isassociated with a tool (71).
 8. A device as claimed in claim 7 ,characterised in that said tool (71) can rotate about the axis of saidrod (701).
 9. A device as claimed in claim 7 , characterised in thatwith said tool (71) there are associated two appendices (710, 711), ofwhich one (710) is used to extract the ring (5) from said carcass (4),and the other (711) is used to insert said ring (5) into said carcass(4).